Mononuclear Lanthanide Complexes: Energy‐Barrier Enhancement by Ligand Substitution in Field‐Induced DyIII SIMs.

Four mononuclear complexes were synthesized through simple self‐assembly reactions, [Dy(L1)2(NO3)H2O] (1), [Tb(L1)2(NO3)MeOH] (2), [Ho(L1)2(NO3)H2O] ⋅ 5.5H2O (3) (HL1=4‐bromo‐2‐((quinolin‐8‐ylimino)methyl)phenol), and [Dy(L2)2(NO3)H2O] (4) (HL2=2,4‐dibromo‐6‐((quinolin‐8‐ylimino)methyl)phenol). They are characterized by their structures and magnetic properties. The magnetic data show that the Dy clusters all have obvious frequency‐dependent magnetic behavior and slow magnetic relaxation effects. The complex 1 under an external dc field with the anisotropic barrier of 14.41 K and pre‐exponential factor τ0=2.70×10−6 s, the complex 4 under an external dc field with the anisotropic barrier of 64.36 K and pre‐exponential factor τ0=2.38×10−7 s. [ABSTRACT FROM AUTHOR]